The present invention relates generally to methods, systems and devices for performing corrective eye surgery. More particularly, the present invention relates to improved computer and laser system interface methods, computer interface programs, and operator system interfaces. The present invention is particularly useful for enhancing the speed, ease, safety, and efficacy of laser eye surgical procedures such as photorefractive keratectomy (PRK), laser in situ keratomileusis (LASIK), and the like.
Laser eye procedures typically employ ultraviolet or infrared lasers to remove a microscopic layer of stromal tissue from the cornea to alter its refractive power. Excimer lasers (i.e. ultraviolet laser), such as the VISX STAR(trademark) or STAR S2(trademark) laser system, use argon and fluorine gas to create a non-thermal laser light to break molecular bonds, in a process known as photoablation. Ultraviolet laser ablation results in the photodecomposition of the corneal tissue, but generally does not cause significant thermal damage to adjacent and underlying tissues of the eye. The photoablation removes stromal tissue to change the contour of the cornea to correct myopia (near-sightedness), hyperopia (far-sightedness), and astigmatism.
In general, existing laser eye surgery systems have included an operator interface for use by the laser system operator in setting-up, controlling, monitoring, and generally directing the laser treatment of the patient""s eyes. The safety and efficacy of a photorefractive procedure depends in part on the operator""s ability to interact with the laser control system using the operator interface. The costs of each surgical procedure are significantly affected by any unnecessary time delays in setting-up or directing the procedure. Unfortunately, existing operator interfaces are less than ideal in a number of aspects.
The photoablation of corneal tissues benefits from precise alignment between the eye and a therapeutic laser. Known laser eye surgical alignment systems typically have a patient seat or bed with the patient seated, lying down, or reclined in a supine position. To align the patient with the laser beam, the operator must manually adjust the seat or bed into alignment with the laser. Additionally, because the seat or bed often has limited speeds and/or ranges of motion the alignment procedure can be quite time consumingxe2x80x94especially when both eyes are to be treated.
Known operator interface display systems also suffer from a variety of additional disadvantages. For example, it may not always be as clear as would be desirable what type of refractive error and/or correction is represented on a controller display. Specifically, hyperopia and myopia designate alternative refractive errors which are opposite in nature, but it may not always be clear whether a negative value in a hyperopic display field designates a myopic characteristic or correction or a hyperopic characteristic or correction. An error introduced at this point would result in the patient""s refractive error being doubled instead of corrected.
Laser ablation of the epithelial layer, an outer layer of the eye, is often performed before the re-sculpting ablation begins. While these epithelial ablations are now controlled from the operator interface, it can be time consuming to reconfigure the system if the epithelial layer is not completely removed from with the initial laser ablation treatment. Finally, known laser refractive surgery systems do not always provide sufficient information to everyone involved in the procedure. In addition to the system operator, the patient and assistant might benefit from procedure and/or system information which is currently directed only to the operator. These limitations detract from the speed, safety, and comfort of known refractive surgical techniques.
For these reasons, it is desired to provide an improved interface for laser eye surgery. In particular, it is desired to have a system capable of automatically aligning the patient""s eye with the laser. Furthermore, it would be desirable to have a system which quickly and automatically aligns the patient""s second eye after the first eye has been treated. It is also desired to have a system interface which would allow the operator to easily determine the refractive characteristics that have been entered. It would further be desirable to provide a system in which the assistant can view system information regarding the procedure, while still being near the patient. It would further be desirable if such a system could easily control the complete ablation of the target portion of the epithelial layer. At least some of these objectives will be met by the system and method of the present invention described hereinafter and in the claims.
The present invention generally provides improved laser eye surgery devices, systems, and methods. The invention generally enhances laser eye treatment by using methods and interfaces which increase treatment efficiency and provide improved system features.
In one aspect, the present invention provides a laser refractive surgery system having a laser that produces a laser beam. The laser defines a longitudinal axis along the path of the laser beam. A patient seat is movable along at least the X and Y horizontal directions. A control system is coupled to the patient seat and laser and automatically positions the seat at a nominal position. At the nominal position, the seat substantially aligns a patient""s first eye with the laser axis. In a particular embodiment, the control system can be adapted to automatically substantially align a second eye with the laser axis.
In another aspect, the present invention provides a laser refractive system having a laser which produces a laser beam that defines a longitudinal axis. A patient seat or bed is contoured to support a patient in a patient position so that first and second eyes of the patient are near first and second nominal axes, respectively. A seat alignment system couples the seat to the laser. The patient alignment system moves the seat, the laser, or both, in response to a nominal position signal so that the beam axis is aligned with the first optical axis.
In yet another aspect, the present invention provides a method for positioning a patient for refractive eye surgery. The method includes the steps of automatically positioning a patient in a first nominal position. In the first nominal position, the patient""s first eye is substantially aligned with a laser. The patient is then automatically positioned to a second nominal position. In the second nominal position, the patient""s second eye is substantially aligned with the laser. In most embodiments, the patient is automatically moved to the second nominal position after the first eye has been treated.
In another aspect, the present invention provides a method for aligning a patient for laser surgery. The method comprises placing a seat in a patient loading position. A control system is activated to move the seat to a first nominal position in which the patient""s eye is substantially aligned with a laser beam axis.
In a further aspect, the present invention provides a laser eye surgery system. The system includes a laser for producing a laser beam. A patient seat or bed is positioned adjacent the laser. A control system is coupled to the laser. The control system has laser operation controls and displays information about the treatment. An assistant display is coupled to the control system, wherein the monitor is viewable from adjacent the patient seat or bed so an assistant can monitor the treatment from the assistant station.
In another aspect, the present invention provides a method of providing treatment information of a laser eye procedure to an operator and an assistant adjacent a patient. The method comprises monitoring treatment information of a laser eye procedure. The treatment information is displayed in real-time on a computer control system and an assistant display. The assistant display screen is aligned substantially orthogonal to the computer control system so the assistant adjacent the patient can view the information displayed on the assistant display.
In yet another aspect, the present invention provides a method for performing corrective eye treatment. The method includes the step of directing a laser beam at a corneal region of an eye of a patient. Information about the treatment is displayed to the operator in real-time on a control station display. Information about the treatment is also displayed to an assistant in real-time on an assistant display, such that the assistant can view the information while adjacent the patient.
In a further aspect, the present invention provides a laser eye surgery system having a laser system for producing a laser beam for refractive surgery on a cornea. A computer control station, having an operator interface and control system, is coupled to the laser system to monitor and control the laser system. Typically, the computer control system is adapted to display on the operator interface a first color with fields displaying myopic refractive information and a second color with fields having hyperopic refractive information. The first color and second color are preferably different colors.
In another aspect, the present invention provides a method of displaying refractive information. The method includes the step displaying refractive information on an edit field. A first background color is provided for the edit fields displaying myopic refractive information. A second background color is provided for the edit fields displaying hyperopic refractive information.
In yet another aspect, the present invention provides a system for removing an epithelial layer from a target region in a cornea during photorefractive surgery. The system includes a laser which produces a tissue-ablative beam. The laser provides an initial uniform epithelial ablative treatment over the region and a refraction altering resculpting ablative treatment. A control system that is adapted to monitor and control the ablative treatments is coupled to the laser. An operator input is coupled to the control system, such that upon actuation of the operator input, the control system actuates the laser to provide an incremental epithelial ablative treatment.
In a further aspect, the present invention provides a system for removing an epithelial layer from a target region in a cornea. The system includes a laser which provides a first ablative treatment and a secondary ablative treatment. A control system is coupled to the laser and is adapted to monitor and control the tissue ablative treatments. An operator input for providing a secondary ablative treatment is coupled to the control system. Upon actuation of the operator input, the laser provides a secondary ablative treatment. In a preferred embodiment, the operator input comprises a button mounted to the control system. Actuation of the button can deliver a pre-determined amount of the tissue ablative beam.
In yet another aspect, the present invention provides a method for removing an epithelial layer from over a stromal layer in a cornea. The method includes irradiating a target region of the epithelial layer with a first amount of ablative radiation. If it is determined that the first amount of ablative radiation did not completely remove the epithelial layer from the target region, the target region of the epithelial layer is irradiated with a pre-determined secondary amount of ablative radiation. In a preferred embodiment, a button is depressed to deliver the secondary amount of ablative radiation.
These and other aspects of the invention will be further evident from the attached drawings and description of the invention.